A temperature-controlled spectrometer system for continuous and unattended measurements of canopy spectral radiance and reflectance
A temperature-controlled spectrometer system for continuous and unattended measurements of canopy spectral radiance and reflectance
复制标题
DOI：
10.1080/01431161.2014.882035
复制
发表时间：
2014-03-04
影响因子：
3.4
通讯作者：
Vesala, Timo
中科院分区：
文献类型：
--
作者：
Drolet, Guillaume;Wade, Tom;Vesala, Timo
本文介绍了一个全自动系统的发展，收集高分辨率的光谱数据在森林足迹。该系统包括一对现成的光谱仪在一个定制的热外壳与固定的偏离最低点向下（目标）指向光纤和向上指向光纤的辐照度测量。这两种仪器通过定制编写和用户控制的软件在所有天气和天空条件下同时采样。该系统安装在一个25米的涡度协方差脚手架塔，约7米的苏格兰松树林树冠。该系统于2010年3月安装在赫尔辛基大学位于Hyytiala的SMEAR-II野外站，并通过爱丁堡大学和赫尔辛基大学之间的联合方案持续运行。该系统旨在通过捕获和分析定义明确的窄光谱特征，捕获植被光利用效率和荧光的日变化和季节变化，但其实施将允许提取与植被生物物理变量相关的进一步光学信号，并提供一个连续的数据流，以验证卫星数据产品，包括植被指数，如光化学反射指数，PRI）以及太阳诱导荧光的光谱指示剂。
This paper describes the development of a fully automated system for collecting high-resolution spectral data over a forested footprint. The system comprises a pair of off-the-shelf spectrometers in a custom-built thermal enclosure with a fixed off-nadir downward (target)-pointing fibre and upward-pointing fibre for irradiance measurement. Both instruments sample simultaneously via custom-written and user-controlled software during all weathers and sky conditions. The system is mounted on a 25 m eddy covariance scaffolding tower, approximately 7m from a Scots pine forest canopy. The system was installed at the University of Helsinki's SMEAR-II Field Station in Hyytiala in March 2010 and has been operating continuously through a joint programme between the Universities of Edinburgh and Helsinki. The system was designed to capture diurnal and seasonal variation in vegetation light-use efficiency and fluorescence through the capture and analysis of well-defined narrow spectral features, but its implementation would permit the extraction of further optical signals linked to vegetation biophysical variables, and provide a continuous data stream with which to validate satellite data products including vegetation indices such as the photochemical reflectance index (PRI) as well as spectral indicators of solar induced fluorescence.